Automatic spray coating apparatus



Feb. 15, 1949. J, A, PAASCHE 2,461,657

AUTOMATIC SPRAY COATING APPARATUS Filed Feb. 26, 1945 3 Sheets-Sheet l Feb. l5, 1949. .1. A. PAAscHE AUTOMATIC SPRAY COATING APPARATUS 3 Sheets-Sheet 2 Filed Feb. 26, 1945 i INVENTOR.

Bgyjfz JMZZ i@ m MIM Feb. l5, 1949. J. A PAASCHE 2,461,657

AUTOMATIC SPRAY GOATING APPARATUS Filed Feb. 26, 1945 5 Sheets-Sheet 3 3 Lj- 143 34 116 1531@ is i Thi: Y IZ/ w 46 J/Z r i I n I 1J [56 l I 13E 3Q l 56 J5@ 425 J Patented Feb. 15, 1949 UNITED STATES PATENT OFFICE 2,461,857 AUTOMATIC SPRAY coArING APPARATUS Jens A. Paasche. Chicago, Ill. Application February 2Q 1945, Serial No. 579,742

(C1. lil-45) 7 Claims. l

'I'he present invention relates to an automatic spray coating apparatus, and more particularly to an improved spray coating apparatus of compact structure particularly suited for coating small objects.

In manufacturing processes it frequently is necessary to give a. protective coating of paint, wax, oil, lacquer or the like to large numbers of small parts or objects. Where such coating is of the type which dries rapidly and does not require baking or drying by heat, or where the coated objects may be removed from a coating machine and placed on conveyor apparatus leading to a baking or drying oven, itis desirable to provide an automatic spray coating machine which is relatively simple and compact and which may be adjusted for the automatic coating of various small objects.

In accordance with the present invention an automatic spray coating apparatus is provided utilizing spray guns or air-brushes which are so controlled as to be operative periodically to coat objects brought in the proximity of the guns by a continuously moving mechanism. Such mechanism may comprise a relatively compact revolving table carrying a plurality of article supports each arranged to be rotated when in the range of the spray guns or air-brushes. Adjustable means may be provided to control the number of revolutions of the supports to build up the coat to the desired thickness.

It is therefore an object of the present invention to provide an improved automatic spray coating apparatus which is relatively compact and economical to manufacture.

Another object of the present invention is to provide an automatic spraying or coating apparatus having a spray gun or air-brush arranged to move in synchronism with an article to be coated.

Other and further objects of the present invention subsequently will become apparent by reference to the following description taken in connection with the accompanying drawings wherein Figure 1 is a perspective view of an automatic spray coating apparatus embodying the present invention;

Figure 2 is a cross sectional view through the base or pedestal of the apparatus shown in Figure 1;

Figure 3 is a partial plan view, with portions of the apparatus broken away to show the mechanism for controlling the automatic movement of and operation of the air-brushes or spray guns;

Figure 4 is a partial front view of the apparatus shown in Figure 3;

Figure 5 is a cross sectional view as seen in the direction of the arrows along the stepped lines 5-5 of Figure 4;

Figure 6 is a partial view, generally corresponding to Figure 3, of a modified form of the present invention;

Figure 7 is a view similar to Figure 5, of the apparatus shown in Figure 6; and

Figure 8 is a detailed view partially in cross section of a portion of the apparatus shown in Figures 6 and 7.

Referring more particularly to Figure 1 of the drawing there is shown an automatic spray coating apparatus having a base I8 which may be in the form of a truncated pyramid or cone so as to house certain apparatus illustrated in Figure 2. Above the base I0 there is positioned a rotatable table I2 which adjacent its periphery is provided with a plurality of article supports I4. Above the table I2 there is a hood I 6 connected at its upper end to a vent pipe I8 which may be provided with a suitable suction fan or connected to a suction outlet apparatus or conduit. The hood I6 has an open front 20 and two side apertures 22 and 24 to permit the article supports I4 and articles carried thereby to enter and leave the hood I6. The hood I6 extends forwardly of the edge of the table I2 and may be provided with a shelf portion 26 and a baille plate 28.

The baille plate 28 shields a substantial portion of the article support I4 from falling vapor or spray from the spray coating brushes or guns. The shelf 26 has an arcuate cut out portion 30 to provide an area, wherein a spray gun support 32 may be moved back and forth so that the spray gun supported thereby may move in synchronism with the movement of an article support I4 on the table I2. The spray gun support 32 comprises a rod terminating at its upper end in a clamping block 34 which in turn may support a plurality of rods 36 and 38 having adjacent their upper ends clamping members 4II and 42 respectively for holding in position a, plurality of spray guns or air-brushes 44 and 46. The bracket 32 is supported by the bifurcated clamping end 48 of an arm Sli which is moved in one direction by an apparatus 52 which engages the article supports I4; and in the other direction by a returning mechanism 54. Underneath the hood I6 and the shelf 26 thereof there is a frame 56 which supports the returning mechanism 54 and which carries also certain other mechanism subsequently to be described and illustrated in detail in Figures 4 and 5.

The base I carries an air conditioning device for dehydrating and cleaning air to be supplied to the air-brushes 44 and 40. The air conditioning device 00 preferably is of the type described in my co-pending application. Serial Number 489,211 iiled May 31, 1943, nowPatent No. 2,393,119 although other types of air conditioning devices may be used. The air conditioning device 50 is provided with an inlet connection 00 which is adapted to be connected by suitable pipes or conduits to a source of uid under pressure such as air. The outlet of the air conditioning device may be provided with a suitable pressure regulating valve 02 which preferably is of the type described in my co-pending application Serial Number 476,605 led February 20. 1943, now Patent No. 2,398,503.

A suitable pressure gage 04 may be associated with the pressure reducing valve 02. The outlet of the valve 62 is connected to a pipe 00 having connected thereto a regulating valve 00 which in turn is connected to a conduit 00 leading to a cam actuated valve 02. The pipe 00 has a branch connected to a regulating valve 04 of the same type as the valve 00 which is connected to a conduit 00 for supplying pressure to a pressure tank unit containing the liquid which is to be applied as a coating by the spray guns or brushes. The spray guns 44 and 40 are connected by suitable conduits 00 and 90 to the pressure material container to which the conduit 00 is attached,

Within the pedestal |0 as may be seen from Figure 2 there is a shelf 92 which supports a motor 94 arranged to drive a gear box 90 supported on the second shelf 00. The motor 04 may be an electric motor connected by a belt |00 to a suitable pulley |02 on the exterior of the gear box 06. The gear box 00 has an'upright shaft |04 which is surrounded by a sleeve |00 which carries a drum I|0 keyed to the sleeve |00. The drum III) is surrounded by an adjustable drag brake I|2 connected to a bracket |I4 which is mounted on the top of a gear box 90. Above the drum I I0 the sleeve |00 is surrounded by the bearing portion ||6 which supports the arm 50 which carries the bracket which supports the spray guns. The sleeve |00 is also keyed to a shaft I|0 which supports the table |2.

The motor 94 drives the turntable i2 by means of the reduction gear box 06 so that the article supports I4 progressively enter the hood I0 through the opening 24 and leave through the opening 22. In order that the speed of the turntable l2 may be maintained relatively steady and constant the brake ||2 is .adjusted to the proper degree of clamping pressure to give such a' result continuously. The brake when the motor 94 is deenergized also operates to quickly stop the turntable I2 so that it does not continue to revolve and pass through the hood a number of article support members I4 without the spray guns operating to coat such articles. The spray guns 44 and 40 are so positioned on the brackets 00 'and 2l by proper adjustment of the clamps 40 and 42 that adequate coverage o! the article is obtained.

Each oi' the supports I4 shortly after entering the hood l0 is rotated so that all sides of the articles carried thereby are properly coated. The spray guns 44 and 40 are moved in one direction in synchronism with the movement of the table |2 and the article supports I4. This is accomplished by the apparatus shown in Figures 3, 4

and 5. The arm 00 carries the mechanism 02 which includes a sleeve supporting member |20 containing a rod or shaft |22 biased in one direction by a spring housed within the housing |20. At its lower extremity the rod |22 is provided with a lever |24 and a cam follower |20. The cam follower bears against a cam |20 secured to a portion o! the assembly on the brackets 50. At the upper extremity the rod |22 is provided with an arm |20 so arranged that when the cam follower |20 is in engagement with the cam |20 the rod |30 will engage one of the article supporting members I4. The article supporting member moving in a clock-wise direction as seen in Figure 3 engages the lever |30 so that the arm 50 is moved at substantially the same angular rate as the turntable I2. Thus the spray guns 44 and 40 supported from the bracket 32 mounted on the end of the arm 50 follow the movement oi the article supports I4. The arm 50 as is apparent from Figures 4 and 5 may have a telescopic portion |02 mounted within the sleeve |50 and adapted to be secured in adjusted position by a clamp |34. Thus the bracket 22 may be moved away from or toward the article support I4.

The arm 50 is moved in a clock-wise direction by the action o! the lever |20 and the cam Iollower |20 until the cam follower |20 reaches the leit extremity of the cam |20. At this point the internal springy within the housing |20 moves the lever |30 in a counter-clock-wise direction sumciently so as to clear the article support I4. When this has occurred. the energy stored in the returning mechanism 54 moves the arm back to substantially the position shown in Figure 3. The mechanism 54 may comprise any suitable energy storage device generally exemplified by the simpler form ot door check. Such device is particularly suited since the initial return movement o! the arm 50 will be fairly rapid and the iinal movement will be appreciably slower so that the lever |00 does not strike the article Support I4 with undue impact. Each of the article carriers I4 comprises a sleeve |00 mounted at spaced intervals adjacent the periphery o! the table I2. Within the sleeve there is positioned a shaft |20 carrying at its lower extremity a gear |40. At the upper end oi the shalt |30 there may be a suitable article carrying portion |42 which in one form is or a truste-conical shape. Other types of article supporting members |42 may be provided in accordance with the type of article to be carried. The bracket 50 has an upper shelf portion |44 on which is pivotally mounted a gear sector |40. The gear sector |40 is pivotally mounted at |40 in the proximity of one end of the sector. The other end of the sector is biased toward the gears |40 by a spring |50 having one end contained in a'bracket |02 which is secured to the shelf |44. Thus as the table |2 moves in a clock-wise direction successive carrying devices I4 reach the proximity o! the end of the gear sector |40 whereupon the gears |40 mesh with the gear sector so that as the table continues to move, each oi the carrying devices I4 is rotated while moving from one end of the gear sector |40 t0 the other end. Thus the carrying devices I4 rotate the articles which are being coated by the spray guns 44 and 40. The arm 50 extends through a suitable opening |54 adjacent the upper portion o! the base I0. and at an intermediate point on the arm there is provided a roller |50 which rides on a lower shelf portion |00 mounted between the channel brackets 00. Thus the outer extremity o! the arm 50 is supported so as to move the guns in a steady manner. The guns are controlled by an air controlled valve 62 having a cam surface actuator |60, which is successively engaged by the article supports I4. The length of each cam surface |60 is such that the valve 62 is actuated for a time equal to permit the arm 50 to reach the distance from one end of the cam surface |28 to the other. The valve I2 is closed during the time that the arm l passes through its return movement by virtue of the action of the energy storage return mechanism 64. Thus the spray guns conserve the liquid and are effective only during the time that an object is in alignment with the nozzles of the Spray Elms.

In the embodiment heretofore described the article supports I4 were rotated by a gear rack engaging gears at the bottom of the support. Another manner of providing for the rotation of the article supports is illustrated in the modification shown in Figures 6, 7 and 8 wherein the arm 60 at an intermediate point is provided with a cylindrical insert |62 within which is mounted a motor |64 which may be an electric motor or a pneumatic motor. Power is supplied to the motor |64 by suitable power conductors or conduits |80. In the arrangement shown. the motor |64 may be an air driven motor whereupon the conduits or conductors |00 serve as inlet and outlet air passages. The speed of the motor may be controlled so that the article support is rotated the desired number of times to build up the coat to the required thickness. The motor |64 is supported by levers |66 pivotally mounted at |66 adjacent one point of the periphery of the cylindrical insert |62. The levers |66 at an inter'-4 mediate point are pivotally connected to an arm or rod |10 which passes through an aperture in a stud |12. The stud |12 is mounted on the arm 60 or on the cylindrical insert |62 therein. Between the stud |12 and the lever |66 there is mounted a spring |14 which biases the motor and the support arm |66 in counter-clockwise direction as viewed in Figure 6. The motor has secured to its shaft a knurled pulley |16. Each of the article supports i4 is provided adjacent its lower end with a friction pulley |16 which may be of a material similar to rubber so as to engage in a good driving relation with the knurled pulley |16 of the motor |64. Each time that the arm 50 returns to its startingy position where the cam follower |26 is at the right side of the cam |26 as seen in Figure 3, the arm 30 engages the lower extremity oi' the article support |4 whereupon the friction wheel |16 engages the motor pulley |16 which is biased toward the friction wheel by the action of the spring |14. The pulley |16 remains in driving relation with respect to the motor pulley |16 until the cam follower |26 reaches the left extremity of the cam surface |28 whereupon the arm |30 is moved away to permit the article support I4 to pass on and the arm 60 to return to its original position.

The operation of the apparatus is believed to be readily understood from the foregoing description. In either modiiication a loading and an unloading position is provided adjacent the turntable|2 so that completed coated devices may be removed and uncoated devices placed on the article supports I4. Where the rotation of the table l2 is in a direction so that the articles pass from right to left through the hood I6 the loading and unloading position would be adjacent to the right of the hood.

As the coated articles pass through the outlet opening 22, they may be subjected to suitable drying conditions such as may be provided by a chamber containing heating elements, heated air, or like drying agents. If desired such chamber may be positioned adjacent the apparatus shown in Figure 1 or may be secured thereto without modifying the principles of operation of the present invention. Obviously such drying chamber or drying apparatus would be employed where the coating is of a type which dries less rapidly than certain other coatings which would be sufiizciently dried in a partial revolution of the table While for the purpose of illustrating and describing the present invention certain preferred embodiments have been shown in the drawings, it is to be understood that such variations in the elements and in their arrangements are contemplated as may be commensurate with the spirit and scope of the invention defined in the following claims.

This invention is hereby claimed as follows:

l. An automatic spray coating apparatus comprising a hood and an exhaust stack connected thereto, a plurality of spaced apart article supports arranged to pass through said hood. means for moving said spaced apart article supports through said hood, an air-brush mounted on a movable support member, means for moving said support member successively in one direction in synchronism with the movement of each succeeding article support said later means including a shaft having at one end a lever adapted to be engaged by successive article supports, a cam follower mounted on the other end of the shaft. and a fixed cam surface for determining the travel of said airbrush support member. and means for restoring said air-brush support to its original position.

2. `.An automatic spray coating apparatus comprising a hood and an exhaust stack connected thereto. a plurality of spaced apart article supports arranged to pass through said hood. means ior moving said spaced apart article supports through said hood, an air-brush mounted on a movable support member, means actuated directly by said article supports for moving said support member in one direction periodically in synchronism with the movement of an article support, and means including a cam for disengaging said first means from said article supports for restoring said air-brush support member to its original position.

3. An automatic spray coating apparatus comprising a base. a turntable mounted on said base, a plurality of spaced article supports arranged adjacent the periphery of said turntable, a spray hood mounted above a portion of said turntable. said spray hood having an inlet and an outlet for said turntable article supports, a spray gun, an arm supporting said spray gun, pivoted lever means adapted to engage directly successive article supports passing through said spray hood vfor periodically moving said arm in synchronism with the movement of said article supports, stationary cam means arranged to maintain said pivoted lever in engagement with an article support for a predetermined amount of travel energy storage means connected to said arm for returning said arm to its original position after a predetermined movement, means for rotating each article support while in alignment with said spray gun. and means responsive to the movement of said article supports for controlling the operation of said spray gun.

4. In an automatic spray coating apparatus. the combination comprising a turntable provided with spaced apart article supports adjacent the periphery thereof, a spray hood positioned above a portion of said turntable, an arm having mounted thereon an air-brush. means. mounted on said arm for engaging an article support for a predetermined length of time thereby to move said arm in synchronism with said article support. a motor mounted on said arm, and driving means connected to each article support for engagement with said motor while said means on said arm is in engagement with said article suport.

p 5. In an automatic spray coating apparatus, the combination comprising a turntable provided with spaced apart article supports adjacent the periphery thereof, a spray hood positioned above a portion of said turntable, an arm having mounted thereon an air-brush. means mounted on said arm for engaging an article support for a predetermined length of time thereby to move said arm in synchronism with said article support. a motor mounted on said arm, andIfrictional driving means connected to each article support for engagement with said motor while said means on said arm is in engagement with said article support.

6. The combination in an automatic spray coating apparatus comprising a turntable provided with spaced apart article supports adjacent the periphery thereof, an arm having mounted thereon a spray gun, means mounted on said arm for engaging successive article supports to move said arm in synchronism with each of said article supports for a predetermined distance, and means for rotating each article support while said ann is moving in synchronisrn therewith. said means including a gear for each article support, and a gear rack plvotally mounted at one end and spring biased adjacent the other end so as to urge said gear rack into a position for engagement with one of said gears, said gear rack being posit Voned in the proximity of the travel oi said arm th reby to cause rotation of each article support or a predetermined time.

7. An automatic spray coating apparatus comprising a power-driven generally circular table provided with spaced apart article supports arranged adiacent the periphery thereof. a spray hood mounted over a portion of said table. said hood being provided with an inlet and an outlet to permit the passage o! said article supports through said hood, an air-brush mounted within said hood, means for moving said airbrush for a predetermined distance in synchronism with the movement of an article support through said hood including an arm having thereon a lever being controlled by a cam follower operating on a cam so arranged as to permit disengagement of said lever with said article support i or a predetermined movement of said arm.

JENS A. PAASCHE.

REFERENCES CITED The following references are of record in the ille of this patent:

UNITED STATES PATENTS Number Name Date 2,015,669 Gravely et al Oct. 1, 1935 2,069,845 Paasche Feb. 9, 1937 2,218,165 Gaebei Cct. 15, 1940 2,358,258 Schweitzer Sept. 12, 1944 2,373,604 Schweitzer Apr. 10, 1945 

